In the carpentry and cabinetry fields, it is standard practice in the construction of openings for windows, doors and the like to provide a "roughed in" opening in the basic structural framing. A prefabricated frame for the opening is then generally installed, with any extra space between the outer dimensions of the frame and the inner dimensions of the rough opening being adjusted with thin strips of material or shims.
When the adjacent interior walls are completed, either by gypsum wallboard ("DRYWALL"), plaster, or other material, there is often a relatively unsightly transition or slight gap between the edge of the finished wall and the frame of the opening. Typically, some form of molding or trim is used both to cover this area and also to provide some decorative transition between the installed frame of the opening and the adjacent wall.
Generally the inner edge of such trim is set back from the inner edge of the corresponding portion of the finished door frame. Obviously, it is highly desirable to provide a uniform spacing completely around the finished opening for this setback distance. Additionally, such molding or trim is almost universally provided with a mitered joint at adjoining corners, such as the corner joint between a vertical and an overlying horizontal trim piece. As it is highly desirable to provide a uniform edge distance completely around the opening, as noted above, the determination of the precise measurements for the finish cuts involved in fabricating and installing such trim or molding can become quite involved.
The need arises for an inexpensive, simple gauge for use in measuring and installing trim or molding for doors, windows and other similar openings, which gauge should be easy to use, usable by a single user, and accurate with a minimal amount of training. The gauge must provide at least some adjustment for possible varying widths of framed openings in order to be temporarily installed thereupon for use. It is also desirable that the gauge require a minimal number of steps in its use, and require no marking or defacing of the finished opening frame. Finally, the gauge should require a minimal amount of calculation in its use, thereby providing a savings in time and effort for the user.